allted
1 µW
- Joined
- Aug 23, 2014
- Messages
- 3
I felt I should put this up here for reference since I used this site for inspiration.
The finished Project
Short Video
http://youtu.be/aDBBVxhfReQ
A group of 4 of us got to play with this for our mechanical engineer design project. The final project was a wireless muscle (emg) controlled skateboard. It was controlled by a wristband on your forearm and each flex or squeeze was used a a mild "kick" to increase speed and hold max speed, if you didn't squeeze then the board slowed to a stop with 5% motor braking. Worked perfect. We used sparkfun emg sensors and 2 arduino nano's to run all that.
For this post I'll just stick to the basic board.
The 3 wheeled design was chosen just to be different, it allowed for large motor and a low deck height. Most of the components were chosen because of various posts here on endless sphere. The board was originally designed to be single wheel in the back, it didn't work. It wasn't as stable and it put a lot of stress on the bracket. With the wheel in the front you also had a fail safe and could just pick up the front wheel to stop acceleration in case of a panic. The bracket was steel that was waterjet and welded, I should have just made it one piece and bent it. The wheel gear was mounted using a custom cnc'd aluminum adapter and a 3d printed piece. The motor mount was 3d printed as well. Complete is was right around 12lbs.
Parts-
Powell Peralta deck - skateshop $60
150-155 trucks wheels - ebay $15
yak wheel 113mm - robotmarketplace $21
gears 16sm 44lg and 9mm HTD belts - robot marketplace, sdp/si ~$50
190kv turnigy - hobbyking ~$100
22v 6s20c 2600mah - hobbyking ~$40
EZRUN-150A-PRO ESC - value hobby $89
hk- gt2b radio/receiver - hobbyking ~$20
Use-
Theoretical max speed was 20.2mph, actual 18.45 measured by phone gps
Battery was good for a hair over 3 miles almost 17 min at 80% throttle carrying 185lbs or 2.3miles in 10:30minutes full throttle
Insane power it would leave you behind if you weren't careful!
Changes-
The 2600maH battery was the best at the time of purchase, now a larger mah rating would help range.
6s20c might be overkill as well, it had so much power.
The belts are a pain, really high tension to be able to handle the torque, and perfect alignment. Chain is cheaper and easier.
The ESC was overkill, the cooling fan wasn't needed, even with it off the ESC never even got warm.
The motor got really hot sometimes, mostly at low rpm's, not sure if the 22v battery was a bit much or if it was with in acceptable heat range and I was just worried for nothing.
The finished Project
Short Video
http://youtu.be/aDBBVxhfReQ
A group of 4 of us got to play with this for our mechanical engineer design project. The final project was a wireless muscle (emg) controlled skateboard. It was controlled by a wristband on your forearm and each flex or squeeze was used a a mild "kick" to increase speed and hold max speed, if you didn't squeeze then the board slowed to a stop with 5% motor braking. Worked perfect. We used sparkfun emg sensors and 2 arduino nano's to run all that.
For this post I'll just stick to the basic board.
The 3 wheeled design was chosen just to be different, it allowed for large motor and a low deck height. Most of the components were chosen because of various posts here on endless sphere. The board was originally designed to be single wheel in the back, it didn't work. It wasn't as stable and it put a lot of stress on the bracket. With the wheel in the front you also had a fail safe and could just pick up the front wheel to stop acceleration in case of a panic. The bracket was steel that was waterjet and welded, I should have just made it one piece and bent it. The wheel gear was mounted using a custom cnc'd aluminum adapter and a 3d printed piece. The motor mount was 3d printed as well. Complete is was right around 12lbs.
Parts-
Powell Peralta deck - skateshop $60
150-155 trucks wheels - ebay $15
yak wheel 113mm - robotmarketplace $21
gears 16sm 44lg and 9mm HTD belts - robot marketplace, sdp/si ~$50
190kv turnigy - hobbyking ~$100
22v 6s20c 2600mah - hobbyking ~$40
EZRUN-150A-PRO ESC - value hobby $89
hk- gt2b radio/receiver - hobbyking ~$20
Use-
Theoretical max speed was 20.2mph, actual 18.45 measured by phone gps
Battery was good for a hair over 3 miles almost 17 min at 80% throttle carrying 185lbs or 2.3miles in 10:30minutes full throttle
Insane power it would leave you behind if you weren't careful!
Changes-
The 2600maH battery was the best at the time of purchase, now a larger mah rating would help range.
6s20c might be overkill as well, it had so much power.
The belts are a pain, really high tension to be able to handle the torque, and perfect alignment. Chain is cheaper and easier.
The ESC was overkill, the cooling fan wasn't needed, even with it off the ESC never even got warm.
The motor got really hot sometimes, mostly at low rpm's, not sure if the 22v battery was a bit much or if it was with in acceptable heat range and I was just worried for nothing.
